As a teacher I have to insure that students should be thinking before they post something. Simple comments can have huge repercussions, simply because something was viewed out of context. Just because you hit the delete button doesn't mean it is gone forever.
Aside from comments, there are many other issues that come from the use of online technology. Two that are of importance to me are cyber bullying and body images. Cyber bullying is the repetition of making someone feel bad online. The bully itself has no way of seeing their effect on the victim. Also, since it is on the web, everyone can see the comments. The second issue is body images. With the use of online media, the notion of having a perfect body has increased. It has also affected many with their self esteem.
The notion of posts being made to the world wide web will never disappear, it is my job as a teacher to insure that students are able to learn how to use the web and post items responsible.